More precisely, the guidance of the aircraft is implemented at least over an intermediate trajectory between a first flight trajectory for a low-altitude flight, and a second flight trajectory which starts at an initial point, and from which trajectory a parachute drop is carried out.
The present invention applies therefore to a parachute drop from an aircraft, in particular from a military transport plane, of elements, especially hardware and/or troops, that must be dropped by parachute onto a determined reception zone on the ground. To be able to carry out such a parachute drop under good conditions, it is necessary for the aircraft to arrive in a stabilized manner, at the right speed (with an appropriate acceleration), at the right altitude and in an aerodynamic configuration appropriate to said initial point corresponding to the start of said (second) flight is be carried out.
Additionally, to be able to carry out such a parachute drop as discretely as possible, the aircraft is generally made to fly along a low-altitude approach trajectory, up to said second flight trajectory, to allow the aircraft to benefit from masking by the terrain and thus not be easily detectable.
Moreover, to attempt to reach said initial point under the aforesaid particular conditions, the pilot of such an aircraft generally has at his disposal only information relating to a point of deceleration which is situated upstream of said initial point, and from which he is advised to decelerate the aircraft. However, this point of deceleration takes no account of the profile of the terrain on the approach to the parachute drop zone, and the pilot must therefore manually adjust the piloting of the aircraft so as to reach said initial point with said aforesaid particular conditions, this naturally being very difficult to achieve.